The present invention relates to a process and system for inscription of coded information on the marginal part of a perforated cinematographic film, and for reading this information.
It is current practice to record, on the marginal part of a perforated cinematographic film, between the successive perforations in the case of 16 mm film, or outside these perforations, in the case of 35 mm film, information which is clear and/or in code, which corresponds to the conditions in which the corresponding sequences were filmed. This information may be relative, for example, to the time of the beginning and end of filming, to the camera, diaphragm and lens used, etc.
Up to the present time, this coded information was recorded in a predetermined matrix form and the information was read through a mask. This modus operandi brings about a linear distribution of the information which does not take into account the variation in speed of the film, in the course of its advance by one step, such variation being effected according to a substantially sinusoidal law. Consequently, the information must be inscribed when the film has stopped.
In another known system, a modulated signal may be continuously inscribed along the track, this signal being similar to a video signal.
None of these systems has proved satisfactory and they necessarily involve the use of relatively cumbersome and complex electronic means.